linux-kernel - Re: [PATCH 4/5] x86-64: Handle exception table entries during early boot

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Date:	Thu, 19 Apr 2012 19:16:09 +0200
From:	Borislav Petkov <bp@...64.org>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	Borislav Petkov <bp@...64.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [PATCH 4/5] x86-64: Handle exception table entries during early
 boot

On Thu, Apr 19, 2012 at 09:59:07AM -0700, H. Peter Anvin wrote:
> The offsets in my code refer to offsets after we push the vector number,
> %rax, %rcx and %rdx onto the stack manually; that is 4*8 = 32 bytes,
> hence the offset.

Ah, sure, you push those upon entry into early_idt_handler, ok.

Btw, just tested the patchset here with the following hunk below and it
looks good.

Also, you can add a revert of ce37defc0f667 as the last one in your
patchset since the comment becomes invalid after it goes in.

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 0a44b90..a3a6299 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -448,6 +448,8 @@ static void __cpuinit bsp_init_amd(struct cpuinfo_x86 *c)
 
 static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
 {
+       u32 dummy1, dummy2;
+
        early_init_amd_mc(c);
 
        /*
@@ -479,6 +481,7 @@ static void __cpuinit early_init_amd(struct cpuinfo_x86 *c)
                        set_cpu_cap(c, X86_FEATURE_EXTD_APICID);
        }
 #endif
+       rdmsr_safe(0xdeadbeef, &dummy1, &dummy2);
 }
 
 static void __cpuinit init_amd(struct cpuinfo_x86 *c)

Thanks.

-- 
Regards/Gruss,
Boris.

Advanced Micro Devices GmbH
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